My research focusses on the evolutionary and psychological origins of cooperation. In particular, I am interested in why and how individuals decide to help others instead of being selfish. To investigate these questions, I mostly study chimpanzees (Pan troglodytes) and Norway rats (Rattus norvegicus) besides humans. Most of my studies are based on predictions derived from game theoretical models that I test experimentally in both the lab and field. Please visit my website for more information and ways to join our lab.